Nope, no thoughts about mathematics. Well, no thoughts that are explicitly about mathematics although -- where sustainability is concerned -- math is always implicitly part of the conversation.
Anyway, I was sitting in a doctor's waiting room recently and picked up a six month old copy of Fortune. Buried toward the back was an article titled "The Trouble with Green Product Ratings". My first impression, after flipping to the right page, was strongly negative. Above even the title was a picture intended to illustrate the article's main premise -- that there are just too many complications, too little information, no real ability to deal with all the trade-offs, and so meaningful green product rating scales are a long way off it not totally impossible. The picture was of water in a disposable bottle, the the trade-off highlighted was that, although the bottles and caps used are 100% recyclable (good), only about 20% of water bottles, nationwide, get recycled (bad).
The fact that the real downsides of bottled water -- the packaging (the defining characteristic of the product) is largely extraneous, reusable (way better than recycled, which is way better than recyclable) alternatives exist, trucks are possibly the least efficient way to deliver water (pipes still work just fine), it's exorbitantly priced and it's a product that serves no real need (just artificially stimulated demand) -- never even entered into the discussion told me that this writer didn't really understand the broader topic.
To give that writer (Paul Keegan) his due, however, he made his point well, and it's a point worth making. Meaningful "green" rating systems are difficult to build because sustainability is inherently complex. The article points out some of the information-access difficulties which aggravate this, and gets into some discussion of industry-specific systems where prioritization of the trade-offs, while still difficult, is at least somewhat simplified.
But what was left in my mind after reading four pages was that the whole effort pretty much missed the point. The largest-scale rating system discussed is being funded and promoted by a (the) big-box retailer. The specific examples included (besides bottled water) a heavily-accessorized iconic fashion doll and a T-shirt featuring a nationally recognized logo. The premise is that if we just do the whole mass-production/mass-distribution/mass-consumption thing more efficiently, we can avoid the imminent need for a whole second Earth.
That CEOs of major corporations recognize the need for change is somewhat encouraging. The fact, though, is that the CEOs, the corporations, the magazine and the writer are all thinking way inside the box (square corners and all). They're not likely to get to the root of the real problem. They're (unsurprisingly) not nearly radical enough.